Safety of Transesophageal Echocardiographyswissecho.ch/en/documents/12_Guidelines_TEE_safety_JASE... · 2012-11-08 · Transesophageal Echocardiography updated the practice guidelines

COMPREHENSIVE REVIEW

Safety of Transesophageal Echocardiography

Jan N. Hilberath, MD, Daryl A. Oakes, MD, Stanton K. Shernan, MD, Bernard E. Bulwer, MD,Michael N. D’Ambra, MD, and Holger K. Eltzschig, MD, PhD, Boston, Massachusetts; Stanford, California; and

Denver, Colorado

Since its introduction into the operating room in the early 1980s, transesophageal echocardiography (TEE) hasgained widespread use during cardiac, major vascular, and transplantation surgery, as well as in emergencyand intensive care medicine. Moreover, TEE has become an invaluable diagnostic tool for the management ofpatients with cardiovascular disease in a nonoperative setting. In comparison with other diagnostic modalities,TEE is relatively safe and noninvasive. However, the insertion and manipulation of the ultrasound probe cancause oropharyngeal, esophageal, or gastric trauma. Here, the authors review the safety profile of TEE byidentifying complications and propose a set of relative and absolute contraindications to probe placement.In addition, alternative echocardiographic modalities (e.g., epicardial echocardiography) that may be consid-ered when TEE probe placement is contraindicated or not feasible are discussed. (J Am Soc Echocardiogr2010;23:1115-27.)

Keywords: Safety, Transesophageal, Echocardiography, Perioperative, Nonoperative, Complications,Contraindications

Accreditation Statement:

TheAmerican Society of Echocardiography is accreditedby theAccreditationCouncil for

From the Department of Anesthesiology, Perioperative and Pain Medicine (J.N.H.,

S.K.S., M.N.D.); Cardiovascular Division (B.E.B.), Brigham andWomen’s Hospital,

Harvard Medical School, Boston, Massachusetts the Department of

Anesthesiology, Stanford University Medical Center, Stanford, California

(D.A.O.); and the Department of Anesthesiology, University of Colorado, Denver,

Colorado (H.K.E.).

Drs. Hilberath and Oakes contributed equally to this work.

Reprint requests: Jan N. Hilberath, MD, Brigham and Women’s Hospital, Harvard

Medical School, Department of Anesthesiology, Perioperative and Pain Medicine,

75 Francis Street, Boston, MA 02115 (E-mail: [email protected]).

0894-7317/$36.00

Copyright 2010 by the American Society of Echocardiography.

ContinuingMedical Education to provide continuingmedical education for physicians.

The American Society of Echocardiography designates this educational activity for

a maximum of 1 AMA PRA Category 1 Credit�. Physicians should only claim credit com-

mensurate with the extent of their participation in the activity.

ARDMS and CCI recognize ASE’s certificates and have agreed to honor the credit hours

toward their registry requirements for sonographers.

The American Society of Echocardiography is committed to ensuring that its educa-

tional mission and all sponsored educational programs are not influenced by the special

interests of any corporation or individual, and itsmandate is to retain only those authors

whose financial interests can be effectively resolved to maintain the goals and educa-

tional integrity of the activity.While amonetary or professional affiliationwith a corpo-

ration does not necessarily influence an author’s presentation, the Essential Areas and

policies of the ACCME require that any relationships that could possibly conflict with

the educational value of the activity be resolved prior to publication and disclosed to

the audience. Disclosures of faculty and commercial support relationships, if any,

have been indicated.

Target Audience:

This activity is designed for all cardiovascular physicians and cardiac sonographers with

a primary interest and knowledge base in the field of echocardiography; in addition, res-

idents, researchers, clinicians, intensivists, and other medical professionals with a spe-

cific interest in cardiac ultrasound will find this activity beneficial.

Objectives:

Upon completing the reading of this article, the participants will better be able to:

1. Recognize the different risk profile for TEE in the operative and non-operative setting.

2. List the absolute and relative contraindications of TEE.

3. Recognize the common sites and mechanisms of potential injury related to TEE in

both the adult and pediatric populations.

4. Appreciate the most common major and minor TEE-related injuries, including oro-

pharyngeal, esophageal, and gastrointestinal injury.

5. Apply recommendations for the prevention of TEE-related orogastric, cardiovascular,

and respiratorycomplications,andappreciate theechocardiographicalternatives toTEE.

6. Identify a subset of procedural risks more specific to the pediatric/infant population.

Disclosures:

Stanton K. Shernan, MD, FASE reported that he is on the speakers’ bureau for Philips

Healthcare, Inc. All other authors of this article reported no actual or potential conflicts

of interest in relation to the activity.

The ASE staff, ASEACCME/CMECommitteemembers and article reviewerswhowere in-

volved in the planning and development of this activity reported no actual or potential

conflicts of interest: Roger Click,MD, PhD; Chelsea Flowers; Rebecca T. Hahn,MD, FASE;

Cathy Kerr; DonaldOxorn,MD; Priscilla P. Peters, BA, RDCS, FASE; andCherylWilliams.

The following members of the JASE Editorial Staff reported no actual or potential con-

flicts of interest in relation to this activity: Julius M. Gardin, MD, FASE; Jonathan R.

Lindner, MD, FASE; Victor Mor-Avi, PhD, FASE; Sherif Nagueh, MD, FASE; Alan S.

Pearlman,MD,FASE; J.Geoffrey Stevenson,MD,FASE; andAlanD.Waggoner,MHS, RDCS.

Estimated Time to Complete This Activity: 1 hour

Transesophageal echocardiography (TEE) has become a standardintraoperative diagnostic technique for the management of patientsundergoing cardiac surgery1-4 as well as other major surgicalprocedures (i.e., lung transplantation5,6 liver transplantation,7 andaortic surgery8). High-risk patients may also benefit from transesopha-geal echocardiographic monitoring in a variety of surgical settings(e.g., lung, renal, abdominal, and head, neck, and chest wall surger-ies).9 In addition, patients in intensive care units (ICUs)10-13 oremergency rooms may profit from the diagnostic information onTEE that cannot be obtained by other modalities in a timelymanner.14-17 Recently, the American Society of Anesthesiologistsand the Society of Cardiovascular Anesthesiologists Task Force onTransesophageal Echocardiography updated the practice guidelinesfor perioperative TEE to assist physicians in the appropriateapplication of TEE and to improve the outcomes of surgicalpatients.9 These comprehensive guidelines focus on highlightingpatient populations likely to benefit from TEE and also list relativeand absolute contraindications to TEE probe insertion.

The American College of Cardiology Foundation and theAmerican Society of Echocardiography, together with key specialtyand subspecialty societies, published appropriateness criteria forTEE in a nonoperative setting in an effort to respond to the need

doi:10.1016/j.echo.2010.08.013

1115

mailto:[email protected]

http://dx.doi.org/10.1016/j.echo.2010.08.013

Table 1 TEE-related injuries

Site Injury

Oropharyngeal Lip bruising/laceration, loose/chipped tooth,displaced dentures, pharyngeal laceration,

perforation of the hypopharynx, accidental

tracheal intubation

Esophageal Odynophagia, dysphagia, laceration/perforation,

Mallory-Weiss tear

Gastric Laceration/perforation, hemorrhage

Miscellaneous Splenic laceration, compression of mediastinal

structures, airway compromise, thermal injury/burn, tongue necrosis

Abbreviations

EGD = Esophagogastro-duodenoscopy

GI = Gastrointestinal

ICU = Intensive care unit

TEE = Transesophagealechocardiography

TTE = Transthoracicechocardiography

1116 Hilberath et al Journal of the American Society of EchocardiographyNovember 2010

for the rational use of imagingservices.18 In general, it is as-sumed that TEE is appropriatelyused as an adjunct or subsequenttest to transthoracic echocardiog-raphy (TTE) when suboptimalimages on TTE preclude obtain-ing a diagnostic study. The indi-cations for which TEE mayreasonably be the test of firstchoice include, but are not lim-ited to, aortic pathology, cardiacvalve dysfunction, percutaneous

noncoronary cardiac interventions, infective endocarditis, atrial fibril-lation or flutter, and embolic events.18,19

Although TEE is considered a safe and relatively noninvasive diag-nostic technique, severe, even life-threatening complications havebeen reported (Table 1, Figure 1). The infrequency of serious compli-cations and difficulties in evaluating rare events limit the identificationof TEE-associated predictors of increased morbidity or mortality.Several retrospective studies involving larger patient populationshave identified inherent risk factors associated with TEE. A literaturesearch was conducted via Medline and PubMed (1966 to June 1,2010), and the bibliographies of retrieved articles were also reviewed.

For practicing echocardiographers, it is important to be familiarwith potential complications of TEE to allow a thorough risk-benefitanalysis on an individual basis. This holds especially true for patientswith preexisting gastroesophageal disease, for whom the decisionabout the benefit versus potential harm of TEE can be difficult.

In this review, we summarize the available literature pertaining tothe risks, complication rates, and overall safety of TEE, with the goalof facilitating the identification of patients in whom alternative echo-cardiographic modalities or other invasive or noninvasive diagnosticstrategies should be considered.

Figure 1 Sites of potential injury related to TEE include oralinjury (e.g., lip or dental trauma), oropharyngeal injury (e.g., lac-eration, perforation), laryngeal injury (e.g., vocal cord trauma,compression of airway structures, inadvertent tracheal intuba-tion), esophageal injury (e.g., laceration, perforation, falsepassage into diverticulum), gastric injury (e.g., lacerations orperforation particularly of fundus or gastroesophageal junction),and gastric bleeding.

GENERAL CLINICAL EXPERIENCE OF TRANSESOPHAGEAL

ECHOCARDIOGRAPHIC SAFETY

Reported rates ofmajor TEE-related complications in ambulatory, non-operative settings range from 0.2% to 0.5%. TEE-associated mortalityhas been estimated to be <0.01% (Tables 2 and 3).20-23 These ratesof adverse outcomes are comparable with those associated withgastroscopy or esophagogastroduodenoscopy (EGD), for which theoverall risk for nonfatal complications is between 0.08% and 0.13%,and the reported mortality rate is approximately 0.004%.24,25 Incomparison with the use of TEE in a nonoperative setting,intraoperative TEE poses a slightly different risk profile, because itinvolves probe placement and manipulation in intubated patientsunder general anesthesia who have frequently receivedneuromuscular blocking drugs. These patients are unable to swallowto facilitate probe insertion and cannot respond to possibly injuriousprobe manipulations. Furthermore, several consecutivetransesophageal echocardiographic examinations or continuousintraoperative monitoring might be required for a subset of surgicalpatients. Overall rates of TEE-related morbidity with intraoperativeTEE, however, have been estimated to be similar to nonoperative pa-tients and range from 0.2% to 1.2%.26-29 In the largest study ofintraoperative TEE–related complications to date, a single-center caseseries of 7,200 patients, Kallmeyer et al.28 reported TEE-associated

morbidity and mortality of 0.2% and 0%, respectively. In contrast,Lennon et al.30 surveyed patients for later complications and suggestedthat rates of major gastrointestinal (GI) injuries (e.g., gastric laceration,hemorrhage, or perforation) could be as high as 1.2%. More than halfof the complications presented >24 hours postoperatively, with onepatient not presenting until day 11. The authors therefore suggestedthat the accurate assessment of overall risk for TEEmay have previouslybeen underestimated given a possible delay in the clinicalmanifestationof TEE-related GI injury.30

Table 2 Incidence of TEE-related morbidity by complication and setting

Complication Ambulatory Intraoperative Pediatric ICU

Dental injury ASA/SCA31 0.1% Kallmeyer et al.28 0.03%Lip injuries ASA/SCA31 13%

Hoarseness ASA/SCA31 12%Pharyngeal discomfort Cyran et al.126 5%

Severe odynophagia Kallmeyer et al.28 0.1%Minor pharyngeal bleeding Khandheria et al.20 0.14%;

Daniel et al.23 >0.01%;Seward et al.22 0.2%

Kallmeyer et al.28 0.01%

Dysphagia ASA/SCA31 1.8% Hogue et al.33 (OR, 4.68);Rousou et al.32 (AO,

7.80); Owall et al.35*

Bronchospasm Daniel et al.23 0.07%; Chan

et al.69 0.06%

Laryngospasm Seward et al.22 0.14%Endotracheal tube

malpositionKallmeyer et al.28 0.03% Stevenson70 0.2%

Inadvertent trachealextubation

Stevenson70 0.5%

Tracheal intubation with

probe

Chan et al.69 0.02%

Airway obstruction Stevenson70 1%–5.5%Compression-related

complications

Greene et al.98 0:50;

Stevenson70 0.6%

Dysrhythmias (AF, VF, VT,

NSVT, AVB)

Daniel et al.23 0.06%; Chan

et al.69 0.1%; Sewardet al.22 0.3%

Stevenson70 0:1,650 Slama et al.92 1.6%

CHF Seward et al.22 0.05%

Perforation Daniel et al.23 <0.01% Kallmeyer et al.28 0.01%;

Chan et al.69 0:1,500;

Lennon et al.30 0.3%

Major bleeding Daniel et al.23 <0.01% Kallmeyer et al.28 0.03%;Lennon et al.30 0.8%

Stevenson70 0:1,650

Mortality Daniel et al.23 <0.01%;

Khandheria et al.20

0.02%; Seward et al.22

0.01%

Kallmeyer et al.28 0:7,600 Stevenson70 0:1,650 Stoddard and Longaker127

0:283

Major morbidity Seward et al.22 0.2% Kallmeyer et al.28 0.2%;

Lennon et al.30 1.2%;

Owall et al.35 0:24

Stoddard and Longaker127

<0.01%

Overall complication rate Daniel et al.23 0.18%;

Khandheria et al.20 2.8%

Kallmeyer et al.28 0.2% Stevenson70 2.4% Khoury et al.94 2.6%; Oh

et al.95 4%; Poelaert

et al.93 0:108

AF, Atrial fibrillation; AO, adjusted odds; ASA, American Society of Anesthesiologists; AVB, atrioventricular block; CHF, congestive heart failure;

NSVT, nonsustained ventricular tachycardia; OR, odds ratio; SCA, Society of Cardiovascular Anesthesiologists; VF, ventricular fibrillation;

VT, ventricular tachycardia.

*No significant difference in the incidence of dysphagia between TEE and no TEE.

Journal of the American Society of EchocardiographyVolume 23 Number 11

Hilberath et al 1117

RISK OF TRANSESOPHAGEAL ECHOCARDIOGRAPHY TO

THE ORAL CAVITY, PHARYNX, ESOPHAGUS, AND

GASTROINTESTINAL TRACT

Risk for Minor Oropharyngeal and Esophageal Injury

The overall incidence of TEE-related minor oropharyngeal injury,including lip trauma, dental injury, hoarseness, sore throat, dysphagia,or odynophagia, has been reported as 0.1% to 13%.28,31 In Kallmeyeret al.’s28 series, dental injury occurred at a rate of 0.03%.Odynophagia severe enough to be investigated by EGDwas reported

in seven patients (0.1%). Endoscopic evaluation of these individualsrevealed linear abrasions in the upper (one patient), middle (onepatient), and lower esophagus (two patients). In a case series of 838consecutive cardiac surgical patients by Rousou et al.,32 TEE wasassociated with an odds ratio for dysphagia 7.8 times greater than inpatients in whom TEE was not performed. Although many of theseevents are frequently minor and self-limited, significant morbiditycan result. In one study, dysphagia was associated with an increasedincidence of aspiration, pneumonia, need for tracheostomy, andincreased length of ICU stay.33 Hogue et al.33 reviewed the charts

Table 3 Complications of TEE in adult patients

Study Population Complications

Chan et al.69 1,700 ambulatory patients Complication rate 0.47% (accidental tracheal intubation,bronchospasm, atrial fibrillation); placement failure

0.73%

Colreavy et al.89 255 critically ill patients Complication rate 1.6%; transient hypotension,oropharyngeal bleeding, pulmonary aspiration

Daniel et al.23 10,419 conscious/sedated patients Complication rate 0.18%; one mortality; placement

failure 1.9%

Hogue et al.33 869 cardiac surgical patients Risk for dysphagia independently correlated withintraoperative TEE, age, prolonged postoperative

intubation

Hulyalkar and Ayd27 Cardiac surgical patients No increase in incidence of 41 prospectively studied

postoperative frank or occult patients, 40 controls;

200 bleeding or gastroesophageal retrospectively

studied complaints from controls

Kallmeyer et al.28 7,200 cardiac surgical patients Morbidity 0.2%, no deaths

Khandheria et al.20 7,134 conscious/sedated patients Complication rate 2.8%; major complications

(laryngospasm, sustained ventricular tachycardia,

congestive heart failure, death) 0.26%; one death

Lennon et al.30 516 cardiac surgical patients Major gastroesophageal complications 1.2%, four

gastroesophageal tears/ulcers, two gastric

perforations, time of presentation < 11 days

Min et al.21 10,000 conscious/sedated patients Mortality 0%; orogastric perforation 0.03% (onehypopharyngeal, two cervical esophageal, no gastric)

Owall et al.35 57 cardiac surgical patients No increased rate of odynophagia, sore throat

Poelaert et al.93 108 critically ill patients One transient ventricular tachycardia

Rousou et al.32 838 cardiac surgical patients Odds ratio 7.8 dysphagia


of 869 patients undergoing cardiac surgery (with and without TEE)and found that 4% subsequently had evaluation by barium swallowfor swallowing dysfunction. Older age was the strongest independentpredictor of swallowing dysfunction (P < .001), followed by theduration of postoperative intubation (P = .001), but the use of intra-operative TEE itself also appeared to be an independent risk factorfor dysphagia (odds ratio, 4.68; 95% confidence interval, 1.76–12.43;P = .003).

Although an association between intraoperative TEE and postoper-ative dysphagia or odynophagia has been suggested,28,32,33 anindependent correlation has not been consistentlydemonstrated.27,34,35 A prospective study byOwall et al.35 randomized57 patients undergoing cardiac surgery to either have or not have trans-esophageal echocardiographic monitoring and reported no significantdifferences in the rates of sore throat or odynophagia. Anothernonrandomized study prospectively examined 41 patients undergoingcardiac surgery with and 40 patients without TEE, as well as retrospec-tive analysis of another 200 cases, and found no difference in anorexia,dysphagia, and sore throat.27 These studies are limited by size and/orlack of randomization. Given the morbidity that may be associatedwith severe dysphagia, further study of this area is warranted.

The incidence of dental injury ranges from 0.03% to 0.1%28,31

and correlates with a patient’s overall dental health. Dentures canalso be dislodged by a TEE probe, highlighting a thoroughpreprocedural assessment of the oral cavity.36 Sriram et al.37 re-ported a case of tongue necrosis and formation of a permanent cleftassociated with TEE probe position in a prolonged cardiac opera-tion. Intraoperative tongue swelling in the setting of TEE has been

described in the past,38 but the majority of tongue pathology inthe perioperative period is attributed to endotracheal tube position,the duration of endotracheal intubation,39 or the surgical procedureitself (i.e., head and neck surgery, prone positioning, and risk forvenous congestion).40

TEE and Orogastric Tract Perforation

Upper GI perforations after TEE have been reported in both pediatricand adult surgical patients,29,30,41-49 with an estimated incidencebetween 0.01% and 0.04%.28,30 This incidence is consistent withthe approximate rate of one to three per 10,000 TEE-related perfora-tions in ambulatory, conscious, or semiconscious patients.21,23 GIperforation is associated with severe morbidity, and depending onmode of management (surgical vs medical) and time to diagnosis,mortality can range from 10% to 56%.25,50 Delayed recognition ofserious orogastric canal injury or perforation can be a problem inheavily sedated patients and in the setting of intraoperative TEE inanesthetized patients. Although evidence of rupture may bedramatic with the sudden appearance of the probe in the surgicalfield,41 excessive orogastric hemorrhage, or subcutaneous emphy-sema, the signs of perforation are frequently subtle and likely to bemasked by sedation or general anesthesia and postoperative intuba-tion and sedation. Patients may present much later with nonspecificsigns such as dyspnea, agitation, fever, or bloody nasogastric aspirates.Symptoms relating to spontaneous esophageal perforation such asMeckler’s triad of vomiting, pain, and subcutaneous emphysemaare rarely present, and according to one study of esophageal

Figure 2 Probe malposition. (A,B) Difficulty during probe insertion can be encountered if the TEE probe is lodged into one of thepyriform sinuses. (C) In addition to causing mucosal injury to the oropharynx, the TEE probe can occasionally become distorted inextreme flexion. Attempts to withdraw a TEE probe in this configuration before advancing into the stomach and unfolding the kinkcan lead to severe esophageal injury.



perforation from all causes, up to 33% of initial chest radiographs arewithin normal limits.51 A high level of vigilance for the potential foresophageal rupture must be maintained when considering the etiol-ogy of immediate postoperative findings such as pneumothorax, pleu-ral effusions, or postprocedural shortness of breath.

Certain areas of the orogastric tract appear to be more susceptibleto perforation than others. One review of EGD reported that rupturesoccurred in the hypopharynx 20% of the time, the esophagus 40%,the stomach 5%, and the duodenum 35%.25 During TEE probeplacement, the parapharyngeal area may be vulnerable to injury ifthe probe gets lodged in one of the pyriform sinuses (Figures 2Aand 2B). The upper esophagus at the level of the cricopharynx mayalso be particularly prone to injury, because the posterior aspect ofthe esophagus at the Lannier triangle, is covered only by fascia.Spasm or hypertrophy of the cricopharyngeal muscle49 or narrowingof the space by osteophytic disease of the cervical spinal column mayfurther increase risk for tissue disruption or perforation (Figure 1). In

a recent, large single-center series of 10,000 consecutive transesopha-geal echocardiographic exams in ambulatory patients, Min et al.21

reported three cases (0.03%) of TEE-associated perforation: onehypopharyngeal and two cervical esophageal. The authors notedthat each case was associated with difficult probe placement andadvanced patient age (>75 years).

An increased risk for perforation is associated with TEE in patientswith gastroesophageal pathology (e.g., Zenker’s diverticulum, esoph-ageal stricture or obstructing mass, fibrosis secondary to prior chestradiation), distorted anatomy (e.g., massive cardiomegaly,42 tracheoe-sophageal fistula or atresia), and resistance to probe insertion41 (Table4). However, perforations have also been documented in patientswith no previous GI disease. One case report of a gastroesophagealjunction perforation in an elderly patient with severe peripheral vas-cular disease undergoing revascularization of the lower extremity sug-gests that rupture could occur secondary to compression of ischemiaprone tissues.43 Some authors have speculated that factors such as

Table 4 Suggested contraindications to TEE

Absolute Contraindications Relative Contraindications

Perforated viscous Atlantoaxial joint disease*Esophageal pathology (stricture,

trauma, tumor, scleroderma,

Mallory-Weiss tear,

diverticulum)†

Severe cervical arthritis*

Active upper GI bleeding Prior radiation to the chestRecent upper GI surgery Symptomatic hiatal hernia

Esophagectomy,esophagogastrectomy

History of GI surgery

Recent upper GI bleed

Esophagitis, peptic ulcer disease

Thoracoabdominal aneurysm

Barrett’s esophagus

History of dysphagia

Coagulopathy, thrombocytopenia

*Causing restricted cervical mobility.

†TEE may be used for patients with oral, esophageal, or gastric dis-

ease, if the expected benefit outweighs the potential risk, provided the

appropriate precautions are applied. These precautions may includethe following: considering other imaging modalities (e.g., epicardial

echocardiography), obtaining a gastroenterology consultation, limiting

the examination, avoiding unnecessary probe manipulation, and usingthe most experienced operator.9


small stature, older age, chronic steroid use, prolonged proceduretime, history of radiation therapy involving the thorax, presence ofcongestive heart failure, and low cardiac output before and after car-diopulmonary bypass may be correlated with increased risk for perfo-ration or serious GI injury.21,44,48

TEE-Related GI Bleeding

GI trauma associated with TEE can, in rare instances, lead to seriousbleeding. At least 13 cases of major upper GI hemorrhage have beenreported in the literature to date.23,29,30,52-56 Such episodes haveinvolved large-volume hematemesis or orogastric aspirates of copiousbright red blood or ‘‘coffee grounds’’ from 500 mL to as much as 9 Lthroughout the postoperative period. The overall incidence of majorbleeding complications after TEE has been estimated to be between0.02% and 1.0%.23,28,30

GI bleeding is often secondary to direct trauma to the mucosa ormechanical disruption of friable tissues (e.g., esophageal varices,esophageal tumor). Other non-GI bleeding, such as cardiac tampo-nade from rupture of an aortic aneurysm,57 rupture of an aorticdissection,58 and splenic laceration during intraoperative TEE,59

have also been described. In a large case series of ambulatory (nonop-erative), conscious transesophageal echocardiographic exams byDaniel et al.,23 fatal hemorrhage occurred in one patient in whomTEE probe insertion disrupted esophageal tissue infiltrated by a lungtumor. Minor pharyngeal bleeding occurred in 0.01% (one of10,218) of the examinations and can lead to aspiration in patientsunable to protect their airways.

Given the potential for TEE to cause injury to the orogastricmucosa, there is a recognized risk for GI bleeding after intraoperativeTEE during cardiac surgery, particularly given anticoagulation andpost cardiopulmonary bypass coagulopathies. St-Pierre et al.56

reported a case of massive hemorrhage after TEE in a patient under-going coronary bypass grafting following an acute myocardial infarc-tion. The patient was fully heparinized for cardiopulmonary bypasswhen the TEE probe was inserted and the echocardiographic examwas performed. Immediately after removal of the probe, 1.2 L ofbright red blood drained from the orogastric tube. SubsequentEGD showed evidence of a mucosal tear near the gastroesophagealjunction, as well as multiple erosions noted within the esophagus.In another case report, an 81-year-old woman undergoing aorticand mitral valve repair and coronary artery bypass surgery developedupper GI bleeding with almost 1 L of bright red blood aspirated by theorogastric tube. EGD showed several linear abrasions in the esopha-gus and a large contusion and mucosal tear at the gastroesophagealjunction.29

Despite these and other reports, multiple studies have failed toshow an increased risk for GI bleeding after TEE, even in the settingof anticoagulation. In fact, cardiac surgery itself is associated withupper GI bleeding, often secondary to bleeding duodenal ulcers orgastric erosions. In a case series of 8,559 patients undergoing cardiacsurgery with cardiopulmonary bypass and no TEE, Egleston et al.60

reported gastric complications in 0.41% of patients and an associatedmortality rate of 25.7%. Thus, many GI injuries may not be due toTEE. Hulyalkar and Ayd27 evaluated 41 patients undergoing cardiacsurgery with TEE matched with 40 cardiac surgical patient controlsin whom TEE was not performed. A retrospective analysis ofadditional 200 randomly selected patients was also performed. Theinvestigators reported no difference between the control and TEE(prospective and retrospective) groups in the incidence of occultblood in nasogastric tube aspirates. Similarly, McSweeney et al.61

examined risk factors for GI complications in patients undergoingcardiac surgery and reported that although the overall incidence ofcomplications in patients undergoing intraoperative TEE wasincreased, TEE was not an independent predictor of major GImorbidity.

Although anticoagulation does not appear to greatly increase therisk for TEE-associated bleeding complications, procedures such asthrombolysis may increase the potential for subsequent bleeding afterTEE.One large study reported severe hemorrhagewith a hemothoraxand shock after rupture of a large intramural hematoma of the esoph-agus in a patient who underwent thrombolysis for a partially throm-bosed prosthetic mitral valve 4 hours after diagnostic TEE.23 Giventhe potential for bleeding complications, placing TEE probes beforefull anticoagulation is generally advised.

Another presumed relative contraindication to TEE is the presenceof esophageal varices (e.g., in liver transplantation patients). Theconcern for injury related to esophageal manipulation stems largelyfrom case reports depicting complications from nasogastric tube oresophageal stethoscope placement in this patient population.62 Theguidelines on the prevention and management of gastroesophagealvarices and variceal hemorrhage in cirrhosis by the AmericanCollege of Gastroenterology63 recommend endoscopic surveillancefor gastroesophageal varices in patients with established diagnosesof cirrhosis. In a recently published retrospective case series in patientswith known varices, Spier et al.64 highlighted the relative safety ofTEE. The authors concluded that adherence to the publishedAmerican College of Gastroenterology surveillance guidelines seemssafe practice in cirrhotic patients but recommend a preproceduralendoscopy for patients who have not previously been evaluated. Todate, there are no reports of procedure-related complications ofTEE in a patient with varices, suggesting that TEE can be performedwithout excessive risk in this patient population.

Figure 3 Gastric probe manipulations. Gastric injury typicallyoccurs in the gastric fundus during deep transgastric probemanipulation, especially when requiring extreme anteflexion tobring the probe inline and in contact with the apex of the heart(e.g., deep transgastric aortic outflow view). The gastroesopha-geal junction is a vulnerable zone because probe manipulationat this level may place the relatively fixed tissues under consid-erable tension.



MISCELLANEOUS RISKS OF TRANSESOPHAGEAL

ECHOCARDIOGRAPHY

Cardiovascular and Respiratory Complications

Reports of cardiovascular complications following TEE (e.g., associ-ated arrhythmias) are rare. In a series of 341 obese patients and323 control patients undergoing TEE, there was one case of atrialfibrillation in the obese group and one case of supraventricular tachy-cardia in the control group associated with the procedure.65 Anotherstudy of 10,419 patients, of whom 88.7%were conscious and the vastmajority without sedation, found three cases of nonsustained ventric-ular tachycardia, three cases of transient atrial fibrillation, and one caseof third-degree atrioventricular block.23 More literature exists on car-diovascular complications of upper GI endoscopy. In 21,946 endo-scopic procedures performed over a 4-year period, there were fourcases of supraventricular tachycardia, two cases of myocardial infarc-tion, and one case of congestive heart failure.66 Tseng et al.67 foundventricular arrhythmias and myocardial ischemia, although mostlysubclinical, to be common in patients with stable coronary artery dis-ease undergoing emergent endoscopy for upper GI bleeds, especiallyin those with concomitant congestive heart failure. The growing useof TEE has led to a larger number of examinations in increasingly illpatients. Patients with cardiomyopathies potentially have a higherpropensity for arrhythmias.68 It is therefore conceivable that the re-lease of adrenergic hormones and possible hypoxemia and hypercar-bia from procedural sedation could act as triggers for arrhythmias.

Respiratory complications associated with TEE have also beendescribed. Intraoperative TEE–related endotracheal tube malposi-tioning was noted in 0.03% of cases in Kallmeyer et al.’s28 studyand can potentially lead to catastrophic outcomes. However, respira-tory compromise primarily occurs in the nonoperative setting andincludes hypoxia, unplanned need for endotracheal intubation(secondary to oversedation or aspiration), accidental tracheal intuba-tion with the probe, bronchospasm, and laryngospasm.20,23,69,70

Methemoglobinemia and ensuing hypoxemia from topicalization ofthe oropharynx with benzocaine in preparation for TEE probeinsertion has also been reported.71 Airway compression is morecommon in the pediatric population, but has been found in adultsas well.72 Arima et al.73 reported airway obstruction during TEE probeplacement in a patient with tracheal distortion from an ascendingaortic pseudoaneurysm. Recurrent laryngeal nerve injury has beenencountered, particularly in the setting of transesophageal echocar-diographic monitoring during neurosurgical procedures with patientsin the sitting position.31 In cardiac surgery, however, Kawahito et al.74

followed 116 patients (64 patients with TEE and 52 patients with noTEE) and did not find a statistically significant difference in theincidence of recurrent laryngeal nerve injury.

Thermal Injury, Infectious, and Chemical Complications

Thermal tissue injury created by the piezoelectric crystal vibrationwithin the probe tip or by direct absorption of ultrasound energyhas also been proposed as a potential mechanism of injury.75

Although animal studies have not demonstrated any histopathologicchanges attributable to ultrasound energy in this setting,75,76 thermalinjury has been suspected in the setting of patients with severeatherosclerosis and possibly poorly vascularized and friableesophageal tissue.43 Although the risk for thermal injury seems to beminimal, measures can be taken to limit the risk for thermal or necroticdamage to the esophageal mucosa. The probe may be set at the min-imal gain and acoustic power necessary to obtain adequate images. In

addition, the power can be turned off during cardiopulmonary bypass,while the probe tip should be kept in an unlocked, unflexed positionwhennot being used. To address the issue of inadvertent heating of theprobe, most probes are fitted with a thermistor to sense increases intemperature and are designed to automatically shut down if a presetthreshold temperature (42�C–44�C) is reached.

The Association for Professionals in Infection Control andEpidemiology has published guidelines for infection prevention andcontrol in flexible endoscopy.77 Current standard high-level disinfec-tion practices use a multistep process that relies on liquid chemicalsterilants followed by a rinsing step with water. The use of aldehydeand nonaldehyde sterilization solutions has decreased endoscopy-related infection rates but carries the risk for chemical burns in caseof insufficient water rinse.78 Moreover, infectious complications(i.e., Legionella pneumophila) have been linked to contaminated rinsewater.79

MECHANISMS OF TRANSESOPHAGEAL

ECHOCARDIOGRAPHY–ASSOCIATED INJURY

TEE Probe Placement

Esophageal and gastric injury has long been a recognized risk associ-ated with diagnostic interventions of the upper GI tract.24,25,80-85

One proposed source of pharyngeal and esophageal injury duringTEE involves improper probe placement. If the tip of the probe isnot centered in the posterior pharynx and instead is placed laterallyinto the pyriform fossa, the probe may bend or ‘‘buckle’’ (Figures2A–2C). Advancement of the probe in this situation may cause thetip to be oriented in an extreme retrograde position. Manipulationor rapid removal of the probe oriented in this manner could causeserious gastroesophageal laceration.86 Similarly, manipulation of theprobe while locked in extreme anteflexion could significantly distortthe esophagus leading to serious mucosal tears or perforation.


TEE Probe Manipulation

Manipulation of even well-placed probes within the esophagus andgastrum has the potential to cause injury (Figure 3). An analysis ofprobe position during short-axis views of the left ventricle demon-strated the probe to be within the esophagus 13.6% of cases, thegastric cardia 13.6%, and the midgastrum 72.7%.87 Significant ante-flexion of the TEE probe tip at the gastroesophageal junction mayput considerable tension on the tissues, causing mucosal disruptionor Mallory-Weiss tears.54,75 In two case reports, manipulation of theprobe within the gastrum resulted in splenic laceration and injury,possibly secondary to torsion of the splenic hilum indirectly throughthe gastrosplenic ligament.59,88 Laceration and even perforation ofthe gastric cardia and lesser curvature presumably from transgastricor deep transgastric probe manipulation has also been reported.30

Pressure-Related Injury

An often postulated mechanism of GI morbidity, though not clearlysupported by the literature, involves tissue injury or necrosis second-ary to pressure at the mucosal-probe interface, especially if the probeis retained for long periods in a flexed or locked position. Animalmodels, however, have failed to identify significant esophageal wallpressures (>17 mmHg) or evidence of mucosal injury even whenthe probe was maintained in maximal flexion for prolonged periods.Similarly, mucosal-probe contact pressures of up to 60 mmHg inhumans have not been associated with identifiable injury.75 O’Sheaet al.76 examined the excised esophagus of monkeys and dogs whohad undergone prolonged (up to 8.5 hours) transesophageal echocar-diographic examinations and found no evidence of erosion ornecrosis, even in fully anticoagulated animals.

TRANSESOPHAGEAL ECHOCARDIOGRAPHY IN SPECIFIC

PATIENT POPULATIONS

ICU Patients

TEE has an evolving role in critical care medicine,89 particularly incircumstances in which TTE has been inadequate (e.g., small endocar-ditic lesions on the aortic valve). A growing body of literaturedescribes the successful use of continuous transesophageal monitor-ing devices in critically ill patients.90,91 The ICU population presentsissues not encountered in the ambulatory setting. Critically illpatients are often ventilator dependent and frequently suffer frommajor cardiopulmonary dysfunction as well as coagulopathies,infections, and malnutrition. Frequently, patients’ altered mentalstatus and the sedation requirements limit their cooperation duringTEE. Nevertheless, studies that have sought to evaluate the safetyand utility of TEE in the critically ill have confirmed its relativesafety in this patient group.89,92-95 One case series of 108consecutive transesophageal echocardiographic exams performedin a medical and surgical ICU within a 7-month period reported noserious complications except for a single incident of transientventricular tachycardia.93 The investigators reported that evenpatients with relative contraindications to TEE, such as esophagitis,esophageal varices, and oozing from the mouth or upper GI tract,underwent TEE without apparent complications.93 Another caseseries of 255 consecutive transesophageal echocardiographic exami-nations in ICU patients was associated with a complication rate of1.6%.89 In that study, the most common complication was transienthypotension related to sedation used for probe insertion.Oropharyngeal bleeding was reported in one patient who had both

uremia and thrombocytopenia. Pulmonary aspiration occurred inone patient in the setting of tracheal intubation in preparation forTEE. Although these reports reflect the overall low complicationrate associated with TEE in ICU patients, they are admittedly basedon relatively small populations and may not fully reflect the degreeof inherent risk. Until more experience with TEE in the ICU isavailable, a degree of caution may be warranted. Therefore, it maybe advisable to initially perform TTE in critically ill patients if feasibleand perform TEE if TTE does not yield the required information.

Pediatric Patients

Until about 1989, the use of TEE in the pediatric population waslimited to older children (aged > 7 years), because available probeswere too large for use in infants or neonates.1 Today, probes as smallas 5.9 mm in diameter are available, and TEE has been performed ininfants.31,96 With the development of miniaturized, pediatric TEEprobes, TEE has been increasingly used in pediatric cardiac surgeryto monitor ventricular function, valvular or structural cardiacabnormalities, and hemodynamic status as well as a guide formedical and surgical intervention in the perioperative period.Advancement in probe technology such as the development ofbiplane pediatric probes and continuous-wave Doppler have furtherenhanced the utility and use of TEE in pediatric patients.

Although few studies have evaluated the safety of TEE in thepediatric population (Table 5), its use, particularly in very small infantsand neonates, presents some risks and considerations not evident inother settings. First, because this population is unable to cooperatewith awake TEE, the procedure is usually performed under generalanesthesia with endotracheal intubation and ventilation.70,97 Giventhe smaller size of these patients, TEE may be complicated bycompression or obstruction of the airway or mediastinal structuresassociated with probe insertion.98-100 Abnormalities of the centralvasculature such as double aortic arch, interrupted aortic arch, ortotal anomalous pulmonary venous connection in this populationmay increase the risk for complications secondary to compressionby the TEE probe. Hemodynamic compromise during TEE has beenreported anecdotally,98 and one series of 272 pediatric patients notedan incidence of 0.07%.96,98 This complication, however, seems tooccur only in very small patients, particularly those with abnormalvascular anatomy. Andropoulos et al.,101 in a careful prospective eval-uation of TEE for cardiac surgery in 25 patients weighing 2 to 5 kg,were unable to detect any hemodynamic perturbations attributableto TEE. The authors suggested that TEE-related hemodynamic compli-cations are rare and should not prevent the use of TEE in small infantswhen otherwise indicated.

More common complications include inadvertent dislodgment ofthe endotracheal tube or advancement of the tube into the mainstembronchus during TEE probe placement or advancement.70,99 Certainprobe manipulations have been particularly problematic. Forexample, hypotension and increased peak inspiratory pressureshave been noted with transgastric views, likely because ofanteflexion of the probe against the diaphragm99 (Figure 3).Inadvertent gastric incision has occurred when the transgastric imageswere being obtained during sternotomy (related to the tenting of thestomach against the anterior abdominal wall).70 These complicationsare clearly correlated with, though not limited to, patients of smallersize and weight.70,96,101

Nevertheless, available evidence suggests that TEE with properlysized probes appears to be relatively safe. Patients as small as 2.4 to6.5 kg have undergone TEE with pediatric probes safely.31,96,102-105

Table 5 Complications of TEE in pediatric patients

Study Number of patients Complications

Bezold et al.128 341 Five ventilatory problems, five failed placementsCyran et al.126 18 One transient pharyngeal pain; two <1-cm areas erythematic at

gastroesophageal junction on EGD

Lam et al.129 59 Four complications (6.7%): desaturation, elevated left atrial pressures,

pulmonary vein narrowing

Muhiudeen et al.102 90 Four complications (4.4%): severe bronchospasm, arrhythmias

Muhiudeen et al.106 127 26 complications (20.5%): 12 mainstem advancements ofendotracheal tube

O’Leary et al.130 104 Two complications (1.9%): one dampening of femoral arterial wave form

with probe flexion, one increased ventilatory pressure

Rice132 399 18 complications (4.5%): nine airway complications (50% of these

patients had trisomy 21)

Ritter103 157 No failed placements, no complications

Rosenfeld133 86 Six complications: two failed placements, four elevated left atrial pressure

Stevenson and Sorensen96 348 17 complications (in 16 patients) (4.6%): airway obstruction, one gastric

incision, failed placement

Stevenson131 667 24 complications (3.5%)

Stevenson70 1,650 3.2% complication rate

Stumper et al.104 25 No complications

Stumper134 261 Six complications (2.3%): one bleeding, two arrhythmias, one unspecified;two failed placements



Although adult TEE probes have been used successfully in patients assmall as 14.7 kg,96 some authors recommend using a pediatric TEEprobe for all patients weighing < 20 kg.96,102 A large case series of1,650 pediatric patients (mean age, 3.6 years; mean weight, 17.2kg) reported an overall complication rate of 3.2%, with no fatalevents reported. Other studies have reported complication ratesranging from1.8% to 8.7%.70One study, however, reported a compli-cation rate as high as 20.4%, which was mostly related to right main-stem endotracheal tube advancement.106 Greene et al.98 evaluated50 infants endoscopically immediately following intraoperative TEE(mean weight, 12.6 kg) and foundmild mucosal injury including areasof erythema (54%), edema (24%), erosion (14.1%), hematoma(22%), and petechiae (4.1%) in up to 64% of study patients. Injurymost often occurred at the level of the cricopharyngeal muscle andmore commonly in smaller patients. Esophageal injury was not iden-tified in another study that involved postmortem examination of in-fants after TEE for congenital heart disease surgery.107 In addition,O’Shea et al.76 evaluated the effect of prolonged manipulation ofa 10-mm-diameter TEE probe on esophageal trauma in fully heparin-ized monkeys weighing 3 to 5 kg and could not identify a significantrisk for gastroesophageal injury. In general, if an appropriately sizedprobe is carefully inserted and manipulated, TEE in pediatricpatients appears to be relatively safe.

RECOMMENDATIONS

Prevention of Orogastric Tract Injury

Given the concerns for significant orogastric tract injury, forcefulplacement or removal of the TEE probe ought to be avoided underall circumstances. Probe insertion should never be attempted in thelocked position. Generous lubrication might decrease friction alongthe mucosa and mucosal folds, while a bite block can help keep the

probe midline and prevent dental injury as well as damage to theprobe itself. If significant resistance is met during initial oropharyngealinsertion of the probe, placement under direct visualization may beattempted. A rigid laryngoscope–assisted insertion technique in anes-thetized patients has been successfully used to prevent mucosalinjury.108 Nonoperative patients under conscious sedation can beasked to swallow to facilitate probe insertion. In pediatric patientsweighing <10 kg, Mart and Rosen109 found that TEE probe insertionwas easier with the patient’s head turned sideways. Unfortunately, noequivalent positioning studies are available in the adult population.Depending on patient anatomy, either head flexion or head extensionwith chin lift can potentially alleviate probe placement into the esoph-agus. Various devices to assist guidance of the probe have beendescribed in the literature, and their use depends largely on individualexperience and expertise or institutional availability.110,111 Reusset al.112 reported the successful use of an esophageal overtube infour patients with previously difficult esophageal intubation. Inpractice, an anesthesiologist could place the TEE probe using directlaryngoscopy if the patient is deeply sedated. In case of continuedresistance to placement or advancement of the probe, alternativeimaging approaches, such as TTE or epicardial echocardiography,should be considered. If, however, the potential diagnostic informa-tion of TEE is deemed crucial, consideration may be given to anurgent gastroenterology consult. In some instances, the TEE probecan still be placed under direct visualization113 or a formal upper GIexamination can precede the study. The case of a high-risk patientwith an esophageal stricture has been published in which the stricturewas dilated, and a TEE probe subsequently placed.114 However,esophageal injury has been reported despite preproceduralesophagoscopy.115 Risk and benefit for each individual patient mustbe very carefully weighed in such situations. Contraindications(Table 4) to TEE probe placement very frequently include a historyof dysphagia. Careful patient assessment for significant swallowing


difficulties and a thorough exammay therefore help identify potentialabnormalities of the orogastric tract and alert the echocardiographerto an increased risk for severe injury.

Prevention of Cardiovascular and Respiratory Complications

Given the potential for airway and cardiovascular compromise duringTEE examination, particularly in nonintubated patients, airway andadditional emergency equipment (i.e., code cart) should be readilyavailable. Patients need to be closely monitored during and afterthe procedure if sedation is administered. Moreover, echocardiog-raphers are to be familiar with the local anesthetics used for airwaytopicalization and their recommended maximum doses to preventdrug-related toxicity. It seems prudent that TEE providers undergoformal training before the administration of intravenous conscioussedation to prevent inadvertent overdosing and potential for hypox-emia and/or hypercarbia. The American Society of Anesthesiologistshas published practice guidelines for sedation and analgesia by nona-nesthesiologists.116 If significant amounts of sedation are to be used ora patient has little physiologic reserve (e.g., low ejection fraction,significant valvular stenotic disease, severe pulmonary hypertension,obstructive sleep apnea, significant pulmonary disease), expertswith particular skills in airway management should be consulted.

ECHOCARDIOGRAPHIC ALTERNATIVES TO

TRANSESOPHAGEAL ECHOCARDIOGRAPHY

In patients with relative or absolute contraindications to TEE (Table 4)or in situations inwhich attempted TEE probe placement is unsuccess-ful, TTE or epicardial echocardiography can be a useful alternative.During open-heart surgery, epicardial echocardiography representsa noninvasive and quite accessible alternative to TEE. Epicardial echo-cardiography was first introduced in the 1970s for the evaluation ofopen mitral commissurotomy.117 Further development of TEE andits advantages of continuous imaging without interruption of theoperation have contributed to the decreaseduse of epicardial echocar-diography.

More recently, epiaortic echocardiography has been used intraoper-atively to assess the aortic cannulation and cross-clamp sites tominimizeembolic complications of cardiopulmonary bypass. This approach hasbeen shown to significantly influence intraoperative surgical decisionmaking.118 Several authors have suggested that epiaortic echocardiogra-phy may occasionally offer superior imaging and evaluation of aorticvalve pathology.119,120 In some circumstances, epicardial imaging mayallow for better Doppler beam alignment and thus permit moreaccurate measurement of valve gradients and valve areas comparedwith TEE. Epicardial echocardiographic measurement of aortic valvearea has recently been validated compared with TEE, TTE, andcardiac catheterization.121 The epicardial approach has also been usedin pediatric cardiac surgery both as an alternative and as a complemen-tary approach to TEE.104 A comprehensive epicardial and epiaorticexam, with correlations to the image planes identified with TEE, hasbeen described.122 Alternative approaches such as substernal echocar-diography or intracardiac echocardiographymay alsoprove to be usefulin the intraoperative and perioperative settings.123,124 Theseinnovations are currently limited by considerations of increased cost,limited windows, time required for examinations, and additionalexpertise necessary125 but may be useful options in selected patientpopulations.

CONCLUSIONS

TEE represents a valuable and generally safe diagnostic and monitor-ing tool for the evaluation of cardiac performance and structural heartdisease and can favorably influence clinical decision making.Although complications associated with TEE probe placement andmanipulation can occur, these events are rare. Awareness of thepossible complications, proper identification, and careful assessmentof patients who are at increased risk for adverse events related toTEE are very important. In those patients, the use of alternativeimaging techniques should be considered to further minimizeTEE-associated injury.

REFERENCES

1. Click RL, Abel MD, Schaff HV. Intraoperative transesophageal echocar-diography: 5-year prospective review of impact on surgical manage-ment. Mayo Clin Proc 2000;75:241-7.

2. Mishra M, Chauhan R, Sharma KK, Dhar A, Bhise M, Dhole S, et al.Real-time intraoperative transesophageal echocardiography—howuseful? Experience of 5,016 cases. J Cardiothorac Vasc Anesth 1998;12:625-32.

3. Eltzschig HK, Shernan SK, Rosenberger P. Ischemic mitral regurgitationduring temporary coronary-artery ligation. N Engl J Med 2004;350:2424-5.

4. Eltzschig HK, Rosenberger P, Loffler M, Fox JA, Aranki SF, Shernan SK.Impact of intraoperative transesophageal echocardiography on surgicaldecisions in 12,566 patients undergoing cardiac surgery. Ann ThoracSurg 2008;85:845-52.

5. Michel-Cherqui M, Brusset A, Liu N, Raffin L, Schlumberger S,Ceddaha A, et al. Intraoperative transesophageal echocardiographicassessment of vascular anastomoses in lung transplantation. A reporton 18 cases. Chest 1997;111:1229-35.

6. Murtha W, Guenther C. Dynamic left ventricular outflow tract obstruc-tion complicating bilateral lung transplantation. Anesth Analg 2002;94:558-9.

7. Suriani RJ, Cutrone A, Feierman D, Konstadt S. Intraoperative transeso-phageal echocardiography during liver transplantation. J CardiothoracVasc Anesth 1996;10:699-707.

8. Kihara C, Murata K, Wada Y, Hadano Y, Ohyama R, Okuda S, et al.Impact of intraoperative transesophageal echocardiography in cardiacand thoracic aortic surgery: Experience in 1011 cases. J Cardiol 2009;54:282-8.

9. Practice guidelines for perioperative transesophageal echocardiography.An updated report by the American Society of Anesthesiologists andthe Society of Cardiovascular Anesthesiologists Task Force on Transeso-phageal Echocardiography. Anesthesiology 2010;112:1084-96.

10. Heidenreich PA. Transesophageal echocardiography (TEE) in the criticalcare patient. Cardiol Clin 2000;18:789-805.

11. Yong Y, Wu D, Fernandes V, Kopelen HA, Shimoni S, Nagueh SF, et al.Diagnostic accuracy and cost-effectiveness of contrast echocardiographyon evaluation of cardiac function in technically very difficult patients inthe intensive care unit. Am J Cardiol 2002;89:711-8.

12. Schmidlin D, Schuepbach R, Bernard E, Ecknauer E, Jenni R, Schmid ER.Indications and impact of postoperative transesophageal echocardiogra-phy in cardiac surgical patients. Crit Care Med 2001;29:2143-8.

13. Tousignant CP, Walsh F, Mazer CD. The use of transesophageal echocar-diography for preload assessment in critically ill patients. Anesth Analg2000;90:351-5.

14. Cicek S, Demirilic U, Kuralay E, Tatar H, Ozturk O. Transesophagealechocardiography in cardiac surgical emergencies. J Card Surg 1995;10:236-44.

15. Redberg RF, Tucker K, Schiller NB. Transesophageal echocardiographyduring cardiopulmonary resuscitation. Cardiol Clin 1993;11:529-35.



16. Memtsoudis SG, Rosenberger P, Loffler M, Eltzschig HK, Mizuguchi A,Shernan SK, et al. The usefulness of transesophageal echocardiographyduring intraoperative cardiac arrest in noncardiac surgery. Anesth Analg2006;102:1653-7.

17. van der Wouw PA, Koster RW, Delemarre BJ, de Vos R, Lampe-Schoenmaeckers AJ, Lie KI. Diagnostic accuracy of transesophagealechocardiography during cardiopulmonary resuscitation. J Am CollCardiol 1997;30:780-3.

18. Douglas PS, Khandheria B, Stainback RF, Weissman NJ, Brindis RG,Patel MR, et al. ACCF/ASE/ACEP/ASNC/SCAI/SCCT/SCMR 2007appropriateness criteria for transthoracic and transesophageal echocardi-ography: a report of the American College of Cardiology FoundationQuality Strategic Directions Committee Appropriateness CriteriaWorking Group, American Society of Echocardiography, AmericanCollege of Emergency Physicians, American Society of Nuclear Cardiol-ogy, Society for Cardiovascular Angiography and Interventions, Societyof Cardiovascular Computed Tomography, and the Society forCardiovascular Magnetic Resonance. Endorsed by the American Collegeof Chest Physicians and the Society of Critical Care Medicine. J Am SocEchocardiogr 2007;20:787-805.

19. Cheitlin MD, Armstrong WF, Aurigemma GP, Beller GA, Bierman FZ,Davis JL, et al. ACC/AHA/ASE 2003 guideline update for the clinicalapplication of echocardiography: summary article. A report of theAmerican College of Cardiology/American Heart Association Task Forceon Practice Guidelines (ACC/AHA/ASE Committee to Update the1997 Guidelines for the Clinical Application of Echocardiography).J Am Soc Echocardiogr 2003;16:1091-110.

20. Khandheria BK, Seward JB, Tajik AJ. Transesophageal echocardiography.Mayo Clin Proc 1994;69:856-63.

21. Min JK, Spencer KT, Furlong KT, DeCara JM, Sugeng L, Ward RP, et al.Clinical features of complications from transesophageal echocardiogra-phy: a single-center case series of 10,000 consecutive examinations.J Am Soc Echocardiogr 2005;18:925-9.

22. Seward JB, Khandheria BK, Oh JK, Freeman WK, Tajik AJ. Criticalappraisal of transesophageal echocardiography: limitations, pitfalls, andcomplications. J Am Soc Echocardiogr 1992;5:288-305.

23. DanielWG, Erbel R, KasperW, Visser CA, Engberding R, SutherlandGR,et al. Safety of transesophageal echocardiography. A multicenter surveyof 10,419 examinations. Circulation 1991;83:817-21.

24. Silvis SE, Nebel O, Rogers G, Sugawa C, Mandelstam P. Endoscopiccomplications. Results of the 1974 American Society for GastrointestinalEndoscopy survey. JAMA 1976;235:928-30.

25. Miller G. Complications of endoscopy of the upper gastrointestinal tract[article in German]. Leber Magen Darm 1987;17:299-304.

26. Khandheria BK, Oh J. Transesophageal echocardiography: state-of-theart and future directions. Am J Cardiol 1992;69(suppl):61H-75.

27. Hulyalkar AR, Ayd JD. Low risk of gastroesophageal injury associatedwith transesophageal echocardiography during cardiac surgery. J Cardio-thorac Vasc Anesth 1993;7:175-7.

28. Kallmeyer IJ, Collard CD, Fox JA, Body SC, Shernan SK. The safety ofintraoperative transesophageal echocardiography: a case series of7200 cardiac surgical patients. Anesth Analg 2001;92:1126-30.

29. Kallmeyer I, Morse DS, Body SC, Collard CD. Case 2-2000. Transeso-phageal echocardiography-associated gastrointestinal trauma. J Cardio-thorac Vasc Anesth 2000;14:212-6.

30. Lennon MJ, Gibbs NM, Weightman WM, Leber J, Ee HC, Yusoff IF.Transesophageal echocardiography-related gastrointestinal complica-tions in cardiac surgical patients. J Cardiothorac Vasc Anesth 2005;19:141-5.

31. Practice guidelines for perioperative transesophageal echocardiography.A report by the American Society of Anesthesiologists and the Societyof Cardiovascular Anesthesiologists Task Force on TransesophagealEchoscardiography. Anesthesiology 1996;84:986-1006.

32. Rousou JA, Tighe DA, Garb JL, Krasner H, Engelman RM, Flack JE III,et al. Risk of dysphagia after transesophageal echocardiography duringcardiac operations. Ann Thorac Surg 2000;69:486-90.

33. Hogue CW Jr., Lappas GD, Creswell LL, Ferguson TB Jr., Sample M,Pugh D, et al. Swallowing dysfunction after cardiac operations.Associated adverse outcomes and risk factors including intraoperativetransesophageal echocardiography. J Thorac Cardiovasc Surg 1995;110:517-22.

34. Messina AG, ParanicasM, Fiamengo S, Yao FS, Krieger K, IsomOW, et al.Risk of dysphagia after transesophageal echocardiography. Am J Cardiol1991;67:313-4.

35. Owall A, Stahl L, Settergren G. Incidence of sore throat and patientcomplaints after intraoperative transesophageal echocardiographyduring cardiac surgery. J Cardiothorac Vasc Anesth 1992;6:15-6.

36. Ahmed N, Shaikh A. Transesophageal echocardiogram causing denturedislodgement with upper airway partial obstruction. J Am Soc Echocar-diogr 2009;22:754.e1-2.

37. Sriram K, Khorasani A, Mbekeani KE, Patel S. Tongue necrosis and cleftafter prolonged transesophageal echocardiography probe placement.Anesthesiology 2006;105:635.

38. Yamamoto H, Fujimura N, Namiki A. Swelling of the tongue after intra-operative monitoring by transesophageal echocardiography [article inJapanese]. Masui 2001;50:1250-2.

39. Bagenyi J, Barankay A. Report on a partial necrosis of the tongue causedby an endotracheal tube [article in German]. Der Anaesthesist 1975;24:136-7.

40. Miura Y, Mimatsu K, Iwata H. Massive tongue swelling as a complicationafter spinal surgery. J Spinal Disord 1996;9:339-41.

41. Spahn DR, Schmid S, Carrel T, Pasch T, Schmid ER. Hypopharynx perfo-ration by a transesophageal echocardiography probe. Anesthesiology1995;82:581-3.

42. Massey SR, Pitsis A, Mehta D, CallawayM. Oesophageal perforation fol-lowing perioperative transoesophageal echocardiography. Br J Anaesth2000;84:643-6.

43. Kharasch ED, SivarajanM. Gastroesophageal perforation after intraoper-ative transesophageal echocardiography. Anesthesiology 1996;85:426-8.

44. Brinkman WT, Shanewise JS, Clements SD, Mansour KA. Transesopha-geal echocardiography: not an innocuous procedure. Ann Thorac Surg2001;72:1725-6.

45. Badaoui R, Choufane S, Riboulot M, Bachelet Y, Ossart M. Esophagealperforation after transesophageal echocardiography [article in French].Ann Fr Anesth Reanim 1994;13:850-2.

46. Muhiudeen-Russell IA, Miller-Hance WC, Silverman NH. Unrecognizedesophageal perforation in a neonate during transesophageal echocardi-ography. J Am Soc Echocardiogr 2001;14:747-9.

47. ZalunardoMP, BimmlerD, GrobUC, Stocker R, Pasch T, SpahnDR. Lateoesophageal perforation after intraoperative transoesophageal echocar-diography. Br J Anaesth 2002;88:595-7.

48. Lecharny JB, Philip I, Depoix JP. Oesophagotracheal perforation afterintraoperative transoesphageal echocardiography in cardiac surgery. BrJ Anaesth 2002;88:592-4.

49. Shapira MY, Hirshberg B, Agid R, Zuckerman E, Caraco Y. Esophagealperforation after transesophageal echocardiogram. Echocardiography1999;16:151-4.

50. Dubost C, Kaswin D, Duranteau A, Jehanno C, Kaswin R. Esophagealperforation during attempted endotracheal intubation. J Thorac Cardio-vasc Surg 1979;78:44-51.

51. Flynn AE, Verrier ED, Way LW, Thomas AN, Pellegrini CA. Esophagealperforation. Arch Surg 1989;124:1211-5.

52. Savino JS, Hanson CW III, Bigelow DC, Cheung AT, Weiss SJ. Oropha-ryngeal injury after transesophageal echocardiography. J CardiothoracVasc Anesth 1994;8:76-8.

53. Latham P, Hodgins LR. A gastric laceration after transesophagealechocardiography in a patient undergoing aortic valve replacement.Anesth Analg 1995;81:641-2.

54. Dewhirst WE, Stragand JJ, Fleming BM. Mallory-Weiss tear complicatingintraoperative transesophageal echocardiography in a patient undergo-ing aortic valve replacement. Anesthesiology 1990;73:777-8.


55. Polhamus CD, Werth TE, Clement DJ, Keogh M, Lewis P. Gastrointesti-nal bleeding complicating transesophageal echocardiography. Endos-copy 1993;25:198-9.

56. St-Pierre J, Fortier LP, Couture P, Hebert Y. Massive gastrointestinalhemorrhage after transoesophageal echocardiography probe insertion.Can J Anaesth 1998;45:1196-9.

57. Kim CM, Yu SC, Hong SJ. Cardiac tamponade during transesophagealechocardiography in the patient of circumferential aortic dissection.J Korean Med Sci 1997;12:266-8.

58. Dalby Kristensen S, Ramlov Ivarsen H, Egeblad H. Rupture of aorticdissection during attempted transesophageal echocardiography. Echo-cardiography 1996;13:405-6.

59. ChowMS, TaylorMA, HansonCW III. Splenic laceration associated withtransesophageal echocardiography. J Cardiothorac Vasc Anesth 1998;12:314-6.

60. Egleston CV, Wood AE, Gorey TF, McGovern EM. Gastrointestinalcomplications after cardiac surgery. Ann R Coll Surg Engl 1993;75:52-6.

61. McSweeney ME, Garwood S, Levin J, Marino MR, Wang SX,Kardatzke D, et al. Adverse gastrointestinal complications after cardiopul-monary bypass: can outcome be predicted from preoperative riskfactors? Anesth Analg 2004;98:1610-7.

62. Ritter DM, Rettke SR, Hughes RW Jr., Burritt MF, Sterioff S, Ilstrup DM.Placement of nasogastric tubes and esophageal stethoscopes in patientswith documented esophageal varices. Anesth Analg 1988;67:283-5.

63. Garcia-Tsao G, Sanyal AJ, Grace ND, Carey WD. Prevention andmanagement of gastroesophageal varices and variceal hemorrhage incirrhosis. Am J Gastroenterol 2007;102:2086-102.

64. Spier BJ, Larue SJ, Teelin TC, Leff JA, Swize LR, Borkan SH, et al. Reviewof complications in a series of patients with known gastro-esophagealvarices undergoing transesophageal echocardiography. J Am Soc Echo-cardiogr 2009;22:396-400.

65. Garimella S, Longaker RA, StoddardMF. Safety of transesophageal echo-cardiography in patients who are obese. J Am Soc Echocardiogr 2002;15:1396-400.

66. Lee JG, Leung JW, Cotton PB. Acute cardiovascular complications of en-doscopy: prevalence and clinical characteristics. Dig Dis 1995;13:130-5.

67. Tseng PH, Liou JM, Lee YC, Lin LY, Yan-Zhen Liu A, Chang DC, et al.Emergency endoscopy for upper gastrointestinal bleeding in patientswith coronary artery disease. Am J Emerg Med 2009;27:802-9.

68. Franz WM, Muller OJ, Katus HA. Cardiomyopathies: from genetics tothe prospect of treatment. Lancet 2001;358:1627-37.

69. Chan KL, Cohen GI, Sochowski RA, Baird MG. Complications of trans-esophageal echocardiography in ambulatory adult patients: analysis of1500 consecutive examinations. J Am Soc Echocardiogr 1991;4:577-82.

70. Stevenson JG. Incidence of complications in pediatric transesophagealechocardiography: experience in 1650 cases. J Am Soc Echocardiogr1999;12:527-32.

71. Birchem SK. Benzocaine-induced methemoglobinemia during transeso-phageal echocardiography. J Am Osteopath Assoc 2005;105:381-4.

72. Nakao S, Eguchi T, Ikeda S, Nagata A, Nishizawa N, Shingu K. Airwayobstruction by a transesophageal echocardiography probe in an adultpatient with a dissecting aneurysm of the ascending aorta and arch.J Cardiothorac Vasc Anesth 2000;14:186-7.

73. Arima H, Sobue K, Tanaka S, Morishima T, Ando H, Katsuya H. Airwayobstruction associated with transesophageal echocardiography ina patient with a giant aortic pseudoaneurysm. Anesth Analg 2002;95:558-60.

74. Kawahito S, Kitahata H, Kimura H, Tanaka K, Oshita S. Recurrent laryn-geal nerve palsy after cardiovascular surgery: relationship to the place-ment of a transesophageal echocardiographic probe. J CardiothoracVasc Anesth 1999;13:528-31.

75. Urbanowicz JH, Kernoff RS, OppenheimG, Parnagian E, BillinghamME,Popp RL. Transesophageal echocardiography and its potential for esoph-ageal damage. Anesthesiology 1990;72:40-3.

76. O’Shea JP, Southern JF, D’Ambra MN, Magro C, Guerrero JL,Marshall JE, et al. Effects of prolonged transesophageal echocardio-

graphic imaging and probe manipulation on the esophagus—anechocardiographic-pathologic study. J Am Coll Cardiol 1991;17:1426-9.

77. Alvarado CJ, Reichelderfer M. APIC guideline for infection preventionand control in flexible endoscopy. Am J Infect Control 2000;28:138-55.

78. Venticinque SG, Kashyap VS, O’Connell RJ. Chemical burn injurysecondary to intraoperative transesophageal echocardiography. AnesthAnalg 2003;97:1260-1.

79. Levy PY, Teysseire N, Etienne J, Raoult D. A nosocomial outbreak ofLegionella pneumophila caused by contaminated transesophageal echo-cardiography probes. Infect Control Hosp Epidemiol 2003;24:619-22.

80. Kavic SM, Basson MD. Complications of endoscopy. Am J Surg 2001;181:319-32.

81. Hart R, Classen M. Complications of diagnostic gastrointestinal endos-copy. Endoscopy 1990;22:229-33.

82. Reiertsen O, Skjoto J, Jacobsen CD, Rosseland AR. Complications offiberoptic gastrointestinal endoscopy—five years’ experience in a centralhospital. Endoscopy 1987;19:1-6.

83. Dawson J, Cockel R. In: Br Med J, Res Clin, editors;. p. 583.84. Enns R, Eloubeidi MA, Mergener K, Jowell PS, Branch MS, Pappas TM,

et al. ERCP-related perforations: risk factors and management. Endos-copy 2002;34:293-8.

85. Augoustides JG, Hosalkar HH, Milas BL, Acker M, Savino JS. Uppergastrointestinal injuries related to perioperative transesophageal echocar-diography: index case, literature review, classification proposal, and callfor a registry. J Cardiothorac Vasc Anesth 2006;20:379-84.

86. Orihashi K, Sueda T, Matsuura Y, Yamanoue T, Yuge O. Buckling oftransesophageal echocardiography probe: a pitfall at insertion in an anes-thetized patient. Hiroshima J Med Sci 1993;42:155-7.

87. Orihashi K, Hong Y, Sisto DA, Goldiner PL, Oka Y. The anatomical loca-tion of the transesophageal echocardiographic transducer during a short-axis view of the left ventricle. J Cardiothorac Anesth 1990;4:726-30.

88. Olenchock SA Jr., Lukaszczyk JJ, Reed J III, Theman TE. Splenic injuryafter intraoperative transesophageal echocardiography. Ann ThoracSurg 2001;72(6):2141-3.

89. Colreavy FB, Donovan K, Lee KY,Weekes J. Transesophageal echocardi-ography in critically ill patients. Crit Care Med 2002;30:989-96.

90. Dark PM, SingerM. The validity of trans-esophageal Doppler ultrasonog-raphy as a measure of cardiac output in critically ill adults. Intensive CareMed 2004;30:2060-6.

91. Valtier B, Cholley BP, Belot JP, de la Coussaye JE, Mateo J, Payen DM.Noninvasive monitoring of cardiac output in critically ill patients usingtransesophageal Doppler. Am J Respir Crit Care Med 1998;158:77-83.

92. Slama MA, Novara A, Van de Putte P, Diebold B, Safavian A, Safar M,et al. Diagnostic and therapeutic implications of transesophagealechocardiography in medical ICU patients with unexplained shock, hyp-oxemia, or suspected endocarditis. Intensive CareMed 1996;22:916-22.

93. Poelaert JI, Trouerbach J, De Buyzere M, Everaert J, Colardyn FA. Evalu-ation of transesophageal echocardiography as a diagnostic and therapeu-tic aid in a critical care setting. Chest 1995;107:774-9.

94. Khoury AF, Afridi I, Quinones MA, Zoghbi WA. Transesophagealechocardiography in critically ill patients: feasibility, safety, and impacton management. Am Heart J 1994;127:1363-71.

95. Oh JK, Seward JB, Khandheria BK, Gersh BJ, McGregor CG,Freeman WK, et al. Transesophageal echocardiography in critically illpatients. Am J Cardiol 1990;66:1492-5.

96. Stevenson JG, Sorensen GK. Proper probe size for pediatric transesopha-geal echocardiography. Am J Cardiol 1993;72:491-2.

97. Fyfe DA, Ritter SB, Snider AR, SilvermanNH, Stevenson JG, Sorensen G,et al. Guidelines for transesophageal echocardiography in children. J AmSoc Echocardiogr 1992;5:640-4.

98. Greene MA, Alexander JA, Knauf DG, Talbert J, Langham M, Kays D,et al. Endoscopic evaluation of the esophagus in infants and childrenimmediately following intraoperative use of transesophageal echocardi-ography. Chest 1999;116:1247-50.

99. Tsai SK, Chang CI, Wang MJ, Chen SJ, Chiu IS, Chen YS, et al. Theassessment of the proximal left pulmonary artery by transesophageal



echocardiography and computed tomography in neonates and infants:a case series. Anesth Analg 2001;93:594-7.

100. Andropoulos DB, Ayres NA, Stayer SA, Bent ST, Campos CJ, Fraser CD.The effect of transesophageal echocardiography on ventilation in smallinfants undergoing cardiac surgery. Anesth Analg 2000;90:47-9.

101. Andropoulos DB, Stayer SA, Bent ST, Campos CJ, Fraser CD. The effectsof transesophageal echocardiography on hemodynamic variables in smallinfants undergoing cardiac surgery. J Cardiothorac Vasc Anesth 2000;14:133-5.

102. Muhiudeen IA, Roberson DA, Silverman NH, Haas GS, Turley K,CahalanMK. Intraoperative echocardiography for evaluationof congenitalheart defects in infants and children. Anesthesiology 1992;76:165-72.

103. Ritter SB. Transesophageal real-time echocardiography in infants andchildren with congenital heart disease. J Am Coll Cardiol 1991;18:569-80.

104. Stumper OF, Elzenga NJ, Hess J, Sutherland GR. Transesophagealechocardiography in children with congenital heart disease: an initialexperience. J Am Coll Cardiol 1990;16:433-41.

105. Muhiudeen I, Silverman N. Intraoperative transesophageal echocardiog-raphy using high resolution imaging in infants and children withcongenital heart disease. Echocardiography 1993;10:599-608.

106. Muhiudeen IA, Silverman NH, Anderson RH. Transesophageal transgas-tric echocardiography in infants and children: the subcostal viewequivalent. J Am Soc Echocardiogr 1995;8:231-44.

107. Laporta D, Kleiman S, Begin L, De Marchie M, Spanier AH. Traumaticperforation of the cervical esophagus: a complication of endotrachealintubation. Intensive Care Med 1993;19:59-60.

108. Na S, Kim CS, Kim JY, Cho JS, Kim KJ. Rigid laryngoscope-assisted inser-tion of transesophageal echocardiography probe reduces oropharyngealmucosal injury in anesthetized patients. Anesthesiology 2009;110:38-40.

109. Mart CR, Rosen KL. Optimal head position during transesophagealechocardiographic probe insertion for pediatric patients weighing up to10 kg. Pediatr Cardiol 2009;30:441-6.

110. Hirabayashi Y. GlideScope-assisted insertion of a transesophagealechocardiography probe. J Cardiothorac Vasc Anesth 2007;21:628.

111. Hirabayashi Y, Okada O, Seo N. Airtraq laryngoscope for the insertion ofa transesophageal echocardiography probe. J Cardiothorac Vasc Anesth2008;22:331-2.

112. Reuss CS, Triester SL, Lynch JJ, Heigh RI, Fleischer DE. Esophagealovertube facilitation of transesophageal echocardiography in patientswith previously difficult esophageal intubation. J Am Soc Echocardiogr2007;20:285-9.

113. Ramjohn J, Paulus DA. Use of transesophageal echocardiography in a pa-tient with Zenker’s diverticulum. J Cardiothorac Vasc Anesth 2006;20:385-6.

114. Spence BC, Hartman GS, Gosselin BJ. Intraoperative esophageal dilationfor TEE probe placement in a patient with an undiagnosed esophagealstricture. J Cardiothorac Vasc Anesth 2005;19:209-11.

115. Ghafoor AU, Schmitz ML, Mayhew JF. Esophageal mucosal tear froma transesophageal echocardiography probe despite preliminaryassessment via esophagoscopy in a patient with esophageal disease.J Cardiothorac Vasc Anesth 2004;18:78-9.

116. American Society of Anesthesiologists Task Force on Sedation andAnalgesia by Non-Anesthesiologists. Practice guidelines for sedationand analgesia by non-anesthesiologists. Anesthesiology 2002;96:1004-17.

117. Johnson ML, Holmes JH, Spangler RD, Paton BC. Usefulness of echocar-diography in patients undergoing mitral valve surgery. J Thorac Cardio-vasc Surg 1972;64:922-34.

118. Rosenberger P, Shernan SK, Loffler M, Shekar PS, Fox JA, Tuli JK, et al.The influence of epiaortic ultrasonography on intraoperative surgicalmanagement in 6051 cardiac surgical patients. Ann Thorac Surg 2008;85:548-53.

119. Frenk VE, Shernan SK, Eltzschig HK. Epicardial echocardiography:diagnostic utility for evaluating aortic valve disease during coronarysurgery. J Clin Anesth 2003;15:271-4.

120. Edrich T, Shernan SK, Smith B, Eltzschig HK. Usefulness of intraoperativeepiaortic echocardiography to resolve discrepancy between transtho-racic and transesophageal measurements of aortic valve gradient—a case report. Can J Anaesth 2003;50:293-6.

121. Hilberath JN, Shernan SK, Segal S, Smith B, Eltzschig HK. The feasibilityof epicardial echocardiography for measuring aortic valve area by thecontinuity equation. Anesth Analg 2009;108:17-22.

122. Eltzschig HK, Kallmeyer IJ, Mihaljevic T, Alapati S, Shernan SK. Apractical approach to a comprehensive epicardial and epiaortic echocar-diographic examination. J Cardiothorac Vasc Anesth 2003;17:422-9.

123. Royse CF, Royse AG, Bharatula A, Lai J, Veltman M, Cope L, et al.Substernal epicardial echocardiography: a recommended examinationsequence and clinical evaluation in patients undergoing cardiac surgery.Ann Thorac Surg 2004;78:613-9.

124. O’Leary PW. Intracardiac echocardiography in congenital heart disease:are we ready to begin the fantastic voyage? Pediatr Cardiol 2002;23:286-91.

125. Shernan SK. Invited commentary. Ann Thorac Surg 2004;78:619.126. Cyran SE, Kimball TR, Meyer RA, Bailey WW, Lowe E,

Balisteri WF, et al. Efficacy of intraoperative transesophageal echo-cardiography in children with congenital heart disease. Am J Cardiol1989;63:594-8.

127. Stoddard MF, Longaker RA. The safety of transesophageal echocardiog-raphy in the elderly. Am Heart J 1993;125:1358-62.

128. Bezold LI, Pignatelli R, Altman CA, Feltes TF, Gajarski RJ, Vick GW III,et al. Intraoperative transesophageal echocardiography in congenitalheart surgery. The Texas Children’s Hospital experience. Tex Heart InstJ 1996;23:108-15.

129. Lam J, Neirotti RA, Nijveld A, Schuller JL, Blom-Muilwijk CM, Visser CA.Transesophageal echocardiography in pediatric patients: preliminaryresults. J Am Soc Echocardiogr 1991;4:43-50.

130. O’Leary PW, Hagler DJ, Seward JB, Tajik AJ, Schaff HV, Puga FJ, et al.Biplane intraoperative transesophageal echocardiography in congenitalheart disease. Mayo Clin Proc 1995;70:317-26.

131. Stevenson JG. Role of intraoperative transesophageal echocardiographyduring repair of congenital cardiac defects. Acta Paediatr Suppl 1995;410:23-33.

132. Rice MJ, McDonald RW, Shiota T, Robinson ST, Sahn DJ. Safety andcomplications of transesophageal echocardiography in children withcongenital heart disease. J Am Soc Echocardiogr 1997;10:404.

133. Rosenfeld HM, Gentles TL, Wernovsky G, Laussen PC, Jonas RA,Mayer JE, et al. Utility of intraoperative transesophageal echocardiogra-phy in the assessment of residual cardiac defects. Pediatr Cardiol 1998;19:346-51.

134. Stumper O, Cromme-Dijkhuis A, Hess J, Godman MJ, Sutherland GR.Pediatric transesophageal echocardiography: safety and indications ofa new diagnostic technique. Circulation 1991;84(Suppl 2):461.

Documents

Safety of Transesophageal Echocardiographyswissecho.ch/en/documents/12_Guidelines_TEE_safety_JASE... · 2012-11-08 · Transesophageal Echocardiography updated the practice guidelines